The present invention comprises a new and distinct Prunus avium cultivar hereinafter referred to by the cultivar name ‘Final 121’. This new Prunus cultivar was developed through a breeding program in Baden Wuerttemberg, Germany with the goal of producing good quality fruit with a late ripening time. ‘Final 121’ was selected from a population of seedlings grown from a controlled cross of Prunus avium ‘Spate von Wedler’ (unpatented, female parent) x Prunus avium ‘Sweetheart’ (unpatented, male parent). The first asexual propagation of ‘Final 121’ was carried out in 2006 by hardwood cuttings in Germany and has been asexually reproduced repeatedly by hardwood cuttings since then. ‘Final 121’ has been found to retain its distinctive characteristics through successive asexual propagations.